A. Field of the Invention
The field of the present invention relates generally to apparatuses and methods for separating an outer portion of food product, such as nuts, from an inner portion of the product. More particularly, the present invention relates to apparatuses and methods, by way of example but not of limitation, for removing the outer hulls of walnuts and pecans. Even more particularly, the present invention relates to such hulling apparatuses and methods that utilize an inner, moveable conical element having brush members configured to remove the outer portion of the food product.
B. Background
Many food products have an outer, non-edible portion that covers and protects an inner portion of the food product. A common example of such food products are nuts. Some nuts, such as walnuts and pecans in particular, have a hull or husk portion that covers an inner nut portion, in which is the edible portion of the nut, commonly referred to as the nut meat. As is known in the art, walnuts and pecans are ripe when the hull still exhibits some degree of softness (i.e., such that it can be indented with the thumb or a finger). Waiting until the hull is black and mealy generally increases the possibility that the nut portion will rot. As a result, the harvesting of walnuts and pecans, which typically involves shaking the nuts from the tree, sweeping the nuts into windrows and then picking up the nuts with a harvester, is typically done when the hull portion of the nut is still a green to brown color. Once harvested, the hull portion of the walnut or pecan is removed and disposed of and the nut portion is cleaned, dried to reduce the moisture content and sorted as necessary. In commercial operations, the drying of walnuts and pecans typically involves the use of apparatuses configured to supply heated air. For non-commercial operations, the drying is achieved by storing the nut portion for several months. Once dried, the nut portion of the walnut or pecan is cracked to remove the shell from the nut meat.
In larger scale commercial operations, it is necessary to utilize an apparatus configured to remove the outer hull portion of the walnut or pecan from the inner nut portion. A number of such apparatuses are known. For instance, U.S. Pat. No. 313,984 to Burckhardt describes a conically-shaped grain hulling apparatus that utilizes rows of tufts made out of metallic brushes and arranged in spiral form on the inner portion of the shell to break and hull corn. U.S. Pat. No. 831,663 to Grohens discloses a rotatably configured conical brush disposed in a conical hulling cylinder for removing the, skin from the nut-kernels of peanuts. A nut huller for removing hulls from walnuts and other nuts is described in U.S. Pat. No. 1,388,026 to Conner. This patent discloses the use of a rotatable plate that cooperates with a horizontally arranged circular brush disposed inside a cylindrical shell to dehull the nuts. U.S. Pat. No. 2,094,880 to Formway discloses a walnut huller that transports the walnuts on an endless belt below a series of removable brushes attached to an inclined brush frame configured to remove the hull from the nut portion without penetrating the shell. U.S. Pat. No. 2,147,022, also to Formway, discloses a walnut hulling device that utilizes a plurality of cutter bars to cut into the hull prior to being engaged by the brushes. U.S. Pat. No. 5,329,845 to Bichel discloses an apparatus for hulling nuts that utilizes a rotatable roller cage comprising a plurality of roller brushes radially arranged inside a chamber to remove the semi-soft fibrous hull found on many nuts, including pistachio nuts. U.S. Pat. No. 5,431,094 to Savage, Sr. discloses the use of an endless belt having a nut engagement portion forming a nut passageway below a rotatable scrubbing mechanism. The patents described above are representative of hulling apparatuses known in the prior art that utilize contact with a brush mechanism to remove the hull of the food product.
Although the prior art discloses a number of hulling apparatuses for removing the hull of a food product to expose the inner portion of the product, there are certain characteristics of the known hulling apparatuses that limit their complete acceptance, usefulness and/or cost effectiveness. For instance, it is well known that the trash particles, such as rocks, sticks and the like, that are collected during the harvesting of walnuts and pecans damage or completely knock out part of the stationary brush mechanism, which creates a groove or channel in the bristles of the brush mechanism. A certain amount of the unhulled food products will tend to follow the path of the bristle-free groove and, as a result, will not have their hulls removed by the hulling apparatus. Because of extra handling and re-hulling and the need to shut down operations to replace the brushes on a not so infrequent basis, this effect can substantially slow the hulling process and increase the cost of hulling food products. In addition, practical limits on the size of the apparatuses substantially limit the amount of area actually available for hulling food products, which slows the ability of the hulling apparatus to handle large quantities of product. What is needed, therefore, is a hulling apparatus and method of hulling that substantially reduces or prevents the movement of unhulled food products through bristle-free grooves. Such an apparatus should provide for increased hulling area without requiring substantial increase in the hulling apparatus itself, be relatively simple to operate and provide for the replacement of brushes, albeit less frequently, as needed.